I think the issue here is that it's quite possible (if often inconvenient) to use a programming language for markup. If it's good at that, I might call it a pr

I think the issue here is that it's quite possible (if often inconvenient) to use a programming language for markup. If it's good at that, I might call it a programming and markup language. I would only call it a programming language if it is good at defining meaningful computation and/or sequencing actions.